1. Field of the Invention
The present invention relates to a system of electronic reprographics and, more particularly, to a system of electronic reprographics having stream printing wherein the printing of jobs may being prior to the completion of scanning of all of the original documents comprising the jobs.
2. Description of the Related Art
In electronic reprographic systems, a document or series of documents comprising print jobs are successively scanned. Upon scanning of the documents, image signals are obtained and stored. The signals are then read out successively and transferred to a printer for formation of the images on paper.
A problem encountered in the electronic reprographic technique, particularly when long jobs are printed, is the lengthy time involved in serially scanning and storing images before printing begins. The "first copy out" time is delayed unnecessarily, thereby increasing the overall time required for printing of the job. This can result in a decrease in overall productivity.
The related art has disclosed systems which reduce job turn around time by beginning a printing operation prior to completing the scanning of all of the originals for the job.
U.S. Pat. No. 4,511,928 to Colomb discloses a system for image reproduction which provides a "print while store" function which allows images to be simultaneously stored and printed. The system includes a primary microprocessor which controls the acquisition and storage of images, and a printer control microprocessor which controls printing functions. In operation, the primary microprocessor receives image data from image acquisition circuitry, stores the received image data, and transfers the stored image data to a printer buffer memory. The printer control microprocessor transfers image data to the printer buffer memory to the printer for printing. The operations of the primary and printer control microprocessors are controlled such that the printer control microprocessor controls printing while further image data is being acquired by the primary microprocessor, thus the "print while store" capability is realized.
U.S. Pat. No. 4,422,102 to Tamura discloses a laser recording apparatus for simultaneously scanning and reading out data from adjacent scan lines. More particularly, Tamura discloses a system in which an original to be recorded is read by scanning the original line by line so as to generate signals corresponding to each line scan. The signals are stored in a memory and while the original is still being scanned, the signals stored in memory are read out for controlling a laser recording apparatus.
U.S. Pat. No. 4,589,035 to Yamanishi et al discloses an image forming apparatus for efficiently producing copies of an original document. While a document is optically scanned to produce image signals related to the scanned document, a first copy of the scan image is formed, and the image signals produced by scanning are also stored for use in printing. Subsequent copies of the scanned document are formed from the signals stored in memory, thus allowing faster reproduction of multiple copies.
U.S. Pat. No. 4,903,146 to Nakahara discloses a digital image forming apparatus wherein a job is printed based upon document information stored in memory. A quick-start operation is described wherein one document is read while another document is being printed.
A research disclosure 31718 to a Document Copier with Job Queuing discloses a copier which enables scanned data to be removed from a job image buffer and transmitted to the writer at the same time data is being written to the buffer. An optimum time for printing is not determined.
While the related art recognizes that printing can be initiated before document scanning is completed, the art does not maximize efficiency of such a system by minimizing job turn around time.